Question

Nikki is walking on the road with a load on her head. She does not do work against gravity.why?

Answer 1

Because the displacement of object is perpendicular to gravity and when perpendicular cos 90=0 so no work is done against gravity

Answer 2

Explanation:

Nikki is walking on the road with a load on her head. The displacement of the object is perpendicular to the force of gravity, hence the force acting at 90 degree is counted as zero and hence there is no work done against gravity. The gravity force plays a very important role in such cases, it makes flexibility based on action and work.